1. Field of the Invention
The present invention relates to a combustion-operating setting tool for driving fastening elements in a constructional component and including a piston guide, a setting piston displaceably arranged in the guide space of the piston guide, a combustion chamber adjoining the piston guide, a receptacle for receiving a propellant charge and adjoining the combustion chamber at an end of the combustion chamber remote from the piston guide, a separation member adjustably arranged between the receptacle and the guide space of the piston guide and dividing the combustion chamber in a first sub-chamber arranged between the receptacle and the separation member and a second sub-chamber arranged between the separation member and the guide space of the piston guide with the separation member having a plurality of through-openings for communicating flow of the combustion gases into the guide space of the piston guide and having an active opening cross-section, and a device for adjusting the setting energy by controlling the combustion gases applied to the setting piston.
2. Description of the Prior Art
Setting tools of the type described above are driven with solid fuels in a powder or pellet form, with the setting piston being driven by combustion gases generated as a result of fuel combustion. With the setting piston, fastening elements can be driven in a constructional component.
German Publication DE 199 83 546 A1 discloses a hand-held, powder charge-operated setting tool in which a setting piston is displaceable in a guide space of a piston guide. At one end of the piston guide, which is formed as a guide cylinder, there is provided a receptacle for receiving a propellant charge and which is adjoined, in the direction of the setting piston, by a combustion chamber. The combustion chamber is divided by a separation member, which is formed as a plate with a plurality of openings. The separation member is fixedly secured in the inner space of the guide cylinder. The setting tool also includes a device for changing the driving force. The changing device adjusts the volume of a portion of the combustion chamber that is adjacent to the setting piston. To this end, the changing or adjusting device has a power adjusting arm arranged on the setting piston and which is engaged by adjusting means in form of a screw. With the adjusting arm, the upper end position of the setting piston and, thus, the volume of the second sub-chamber above the setting piston can be adjusted. According to another embodiment, sidewise of the second sub-chamber, there is provided an additional chamber that is connected with the combustion chamber by an adjustable valve. The volume of the additional chamber is adjusted with a displaceable plate that forms a wall of the additional chamber.
The drawback of the adjusting device consists in that a number of additional measures need be taken which require an additional constructional space and noticeably increase the production costs.
Accordingly, an object of the present invention is a setting tool of the type described above in which the drawbacks of the known setting tool are eliminated and a simple setting energy regulation is achieved.